Ice-making machines are well known in the art and many designs have been considered. For example, Applicant's U.S. Pat. No. 4,796,441 issued on Jan. 10, 1989 discloses an ice-making machine having a chamber with a fluid inlet to receive a brine solution from which ice is to be made and a fluid outlet to permit the egress of an ice-brine slurry from the housing. The interior surface of the chamber defines a heat exchange surface. A blade assembly is mounted on a rotatable shaft extending through the centre of the chamber. The blade assembly is in contact with the heat exchange surface. A motor rotates the shaft at a rate such that the interval between successive passes of the blade assembly over the heat exchange surface is such so as to inhibit the formation of ice crystals on the heat exchange surface.
A tubular jacket surrounds the chamber. A refrigerant inlet and a refrigerant outlet communicate with the space between the jacket and chamber and are positioned at opposed ends of the ice-making machine. Refrigerant flowing from the inlet to the outlet boils and in so doing, cools the brine solution in contact with the heat exchange surface. Refrigerant leaving the ice-making machine via the outlet is compressed before being fed back to the inlet. Rings are welded to the jacket at laterally spaced locations to provide structural stability to the ice-making machine allowing it to withstand internal pressures. Although this ice-making machine works satisfactorily, it is time consuming and expensive to manufacture. Accordingly, improved but less expensive ice-making machines with increased efficiency are continually being sought.
It is therefore an object of the present invention to provide a novel ice-making machine and a heat exchanger therefor.